Pipe-line control system



Sept. 28, 1943. s. s. SMITH PIPE LINE CONTROL SYSTEM Filed Aug. 29, 1942 2 Sheets-Sheet l Nw@ SJ HQE A@ mm@ l.

s; s, SSM

PRESSURE l 400 lbs Sept. 28, 1943. S. s, SMITH *Y 2,330,755

PIPE LINE CONTROL SYSTEM Filed Aug. 29, 1942 2 Sheets-Sheet 2 200 bbls/ hour? t: *N* 2O MILES d) 2O MILEs Q) 2O MILES Q) 2O MILES Q) STATION STATION STATION STATION STATION A B c D E 4MM F fe 1I Inventor: Sydney S. SmI'fh Patented Sept. 28, 1943 sydney s. smith, scar Shell Development C sdale, N. Y., assigner to ompany, San Francisco,

Calif., a. corporation of Delaware Application August 29, 1942, Serial No. 456,723

(Cl. 10S-1l) 4 Claims.

This invention pertains to pipe line control systems, and relates more particularly to an automatic system of controlfior pipe line pumping stations. v i

The present control system is particularly suitable for pipe lines whichcan be rapidly constructed from readily available standard materials and equipment, such lines being useful in following moving army fronts, supplying advance air fields or supply depots, or, in general, conveying gasoline, fuel, or anyfother liquid, such as water, to difiicultly accessible places, or to places where a shortageof these commodities may have' developed. A pipe line system'of this type `will in general i comprise a` suitably coupled pipe line adapted to be laid directly onthe ground at a rapid Vrate, gate andcheck Valves in the line at suitable intervals to permit the liquid flow to be stopped at any desired point-,in case of emergency,`and pumping trucks or trailers and spaced `from each other at distances such, for example, as twenty miles along the line. i

`It is a particular object of this invention to provide an automatic controll system for pipe lines of the type dened above, whereby pipe line pressures `and pumping rates farefunctionally controlled by the pipe line pressures.

It is also an object of this invention to provide for the purposes of this control a system comstations mounted on movable units such as for the above purposes an arrangement of con` trol apparatus of rugged and simple construction adapted to be installed on a movable base together with other pumping station equipment, and requiring for` its operation no other source of power except that available at said pumpingstai tion.

prising, in combination, pressure-responsive bypass valves and pressure-responsive speed regulators for the pipe line Apumping equipment.

It is also an object of this invention to apply the above `control system'to manner that the flow therein may be stopped at any desired point without generating undesirable pressures eXceeding-a predetermined maximum value; that the pipe line may be maintained at a desired'. pressure as a closed system under stopped flow conditions; `andvthat the pipe line flow may be restarted without, creating undesirable pressure drops aways of the pumping equipment. f

It is also an object of this linvention to apply the above control to apipe linesystem compri.;- ing aplurality of spaced pumpingstations in such a mannerthat the system normally operates at with all pumping sta-r a predetermined Iflow rate K tions in operation, 'and automatically readjusts itself to a lower predeterniined flow rate when a pumping station or any ,numberl of non-adjacent pumping stations are notr in operation. l It is also an `objeotof` this 'invention to provide pipe lines insuch av i through an inlet passage 22,

It is, however, understood that although the present inventionis described` in connection with a pump line of the particular type dened above; it is in no regard limited to 'pipe lines of said type, but may beusedto control pressures'and flow or pumping rates in pipe lines of any desired type or capacity.

`Other objects and features of this invention willbe understood from the following description, taken with reference to the attached draw inga'Wherein:Y i i Fig. 1 is a sohem tic diagram of the-present control system in application to a pipe line pumpingstation; r Figs. 2, 3 and 4 are pressure diagrams illustrating the operation of the present` system under different sets of cohditionsfV l Referring to the drawings, Fig. Kl shows a pumping station installation on a ipe line1l, provided with a check valve Ill and gatevvalves' t2 and l3,.

the direction `of flow being indicated by arrows.

A conduit I5 by-passes said valves and is connected to the pipe line lll through gate valves l5 and Il.

A Dump, acting piston reciprocating pumpschematically Shown at 29, takes suctionon the conduit I5 under pressure, `by means of a vlave box 23 corn-Vl prising inletvalves 24 and 24a, vand `discharge valves 25 and 25a, through a discharge passage or pipe 28. i i

The passage y2,3 has -two bran-ches 2da and 28h; opening in parallel to the conduit l5 downstream of the inlet passage shown at l and 2, valve l being located inthe passage ory branch 28h, valve 2 in the conduit l5 betweenthe points at which branches 28a and 23h open to said conduit.

Valves I and 2 are normallyyclosed, and o" the pressure-responsive, preferably spring-'loaded diaphragm type, although piston-.type valves, such as shown for simplicity inthe drawings, may equally well be used.

`Valve |is responsivetolpressuresin the outlet passage 23, that" s,'t`oV the pump discharge preferably such as a duplex'doubleand delivers the iluid` 22, thesuction and the pres-` sure sides of the pump being separated `from eachA other by control or relief valves schematically.

tion withitheeinlet passage 22; that is, to; the? pump suction pressure, and its loading spring 2| may be pre-set or adjusted, by means such as. diagrammatically shown in the form of a regulating screw 27, to cause said valve to open .whenrr the suction pressure reaches a predetermined high value.

The pump 20 is actuated bya'primeemoverll'.

having a speed-regulator mechanism 6! responsive to control means to be described hereinbe` low, whereby said prime-mover and pump are automatically maintained'at a speed suitable for a; particular. phase: of operations f of.` the presenti system.f

The@ speed-:regulator tl mayf be ofi' any desired?. type depending onthe typefof: thevfprimefrnover; used; Thus;` with n steam; ginesathefreguiator: Si. may, be' ai. throttle; car-- b-uretor or fuel-injector device; with electric. motors, it: may; besa afre-ldrrheosta't; etc:

The` control 'systeme ,forfthe :speed: regulator of th'ecprimeemoverr comprisesxfan auxiliary. orrcon.` trirl-y pum-p` 63,' driven z through a.; gear.' system,A chain or'beltwlhirom ajsuitaol'ezf actuating party otzthe prime-mover 682 The pump 63 forms part of acicsed; circuit' comprisingfa reservoiriandzaapipefflconnected totsaictreservoir:andf .to the intakerand :discharge ofithepumps':

The system of pump 63, reservoir-653' and pipe'. lisfilledrwith axrelatively smallvlquantity, such, for-examplef,1.asrorre gallon; of: asi suitable liquid, such as lubricating oil, which is circulated through'itlref. reservoirr65 between'v the discharge and the intakeaoftpump :63;

The control systemris-rconnected, byA means' such; for example; as a::liquid'+1led pipe 69,' comprisingfadiaphragm device'. 68T, with the speed regulatorv 6I of the'Iprime-mover.

Agvazriablel orifice; .such as an adjustable needle valve schematically. shownv at 10i, is insertediin It will be understood that when the-needle` vvalve'is': adjustedtoanopening of predetermined sultin an: increased throughput-offtlie control pumpv E3; which' inl turn'r willcause' aigreater-y pressure dropaacross theorice'l; and-a higher pressure in' tha-tportion ofthe pipe-67 between" the discharge of the pump 63 and the ori'celtl.'- 'Iliis' pressurewillbeetransmitted, Vhym'eans of tirefdiapliragnin 68 and pipe 5'9, tothelspeed reggula-torl, andwill"actuatethe-latterrto reduce' thespeed 'off-thefprim-e^mover^ Bi; thus bringing it'ljack'to normal speed.I

Ina: similar. Way, 'a reduction in the speed. of' the prime-mover is correct'ed'an'd'brought't back. to"norma1ithrougli a decrease of'pressureinthe circuit of pump 63.

.In ,addition 'to vtlie oriil'ce '15,'. the, circuit of. pump 63"is provided with t 'reemorediaphragmcontrolled' "variable orifices "or needle valves. schematically shown at 3,74, and. 5,.,which. are. responsive, topressureson` the. discharge or. suction sides of.v the main `pump. 21k-and. Serve t1.,

regulate the speed of the prime-mover as a func' tion of said pressures.

The three units 3, 4 and 5 are installed in. series in the pipe 61 between the discharge oi the control pump 63 and the Variable orice lil. Each of these units comprises a housing 32, 42 and 52, respectively, containing a diaphragm, 33, 43and 53, carrying on .one.sideavalve stem or'` needle,y 34; 44' anni,"y 54,l adapted tor-restrict the W through the pipe 671' In unit 3, the other side of the diaphragm is irrcommunication, through a pipe 35, with the pressurein pipe 28, that is, with the discharge pressure of the pumpv 20. Unit 3, therefore, restricts the ow through the pipe El with increasing. discharge pressures of the pump 20.

In unit 4, the other side of the diaphragm is inxcommunication, through pipes 45 and 55, with the pressure in pipe I5, that is, with the suction pressure ofthe pump 20. Unit il, therefore, restricts the now f through thefpipef 6l l with; increasing suction pressuresfof.' thefl pump 52D.

In vunit 5; the same-sideral.rthezdiaphragm;53; which carries the control stem 54 attacheckthereito is in. communicationrwithf the; strctiom side ofpumpZtl; Unit 5; thereiore;.restricts the new through pipe-6l with decreasing suction; pres?- sure' of the-pumpzy.

Each of the: units-3; IlA 'and-.- 5a is separately?l ad;-- justable for.' closing th :passagethrou-ghpipe EL to anl aperture, smaller-f than 'that'. tos-which; thei orifice of control .10.v had.' been 1 set: ,TheseV` units: are thus independently capableeof.:restrictingthe: flow in the pipe 61 to an adjustable valuelfsmail-ler 'l than that.t permitted by; the: control: lll:

When. any of the unitsrB, 'd2-aud.' s such small zaperturewsizefin respon-setto discharge or suction 'pressure:variations-:crine:nrranzpump 20, .the resulting.; increased: pressure; in: the pipe.-v 51 acts through the diaphragm@ 68 to. slriw` down theprime-zmovers'60;v Thusany oneforfawome bination of said :control .runitscacanfzslowror-r. throttle the primer-mover'belowri itsxnormal.- operating` speed, or, in primefmover.

Thelhigh 1 discharge pressure;` control a 3 isf.. ad:- justed. tov throttle Vthe primer-mover: when the: dischargeA pressures' oi/ the pump 25:. reaches.: a: high value slightly-below that iatfwhich `Ltlieiliigh p ressurefrel-iefl valve. Ii issets-tonl operate.. For example, .if the reliefvalvee l is settogopen atta. discharge pressurefof:` 650 lbs;,..thefcontrol .3fmayy be setto -throttlezthe vprim-eernovernattaf-.dis4 charge pressure' of 625 lbs. 'Ihe controlz3; may;` however; be. provided'with aniadjustable stop 3|. so

that thefminimumispeed fofthe prime-:mover fun'- cler 'the effect of; saidcontroller isreduoed. tu: as

predetermined fractiony such foi-r example, as:

one-haliofits normal speech. Thisfprevents the:

enginel from stopping, A and;v if l the: liner-is.: closerl somewhere vdownstream of thezrstationg. insuresV that the engine-willrun atransuiicient speed-.to permit: the'pressure to build; above;` the 625: lbs.-A point and `up to .af G50-lbs. pressure,` thuscaus ing the relief valvefto` operate-,v aswillbeqde scribed thereinbelow.

The.I high suctionpressure control. lvv isf adjusted to. throttle the prime-mover? when the. suction Ipressure rises vjust :abovethe point where f the` high suction. relief valve. 2fopens; Fory example, if the valve.2.is.set,-to openata suction pressure of 400 lbs;, the controlv Lmay beset. to4 operate at 425f1bs., atvwhich point. itnvill` slow the prime-mover. to. an idling speed, .where it. will` operate.withoutdoing..worlon..the.line (the .high

certain cases, completelm'stop said".

ting recirculation around pressures at the pump station are reduced ,to

120 lbs.` andfator near itsl maximum dischargel as from `58,0 to 625 lbs., because station A is trying to deliver 200` bbls.:per hour,`

suctionrelief Valve 2 being open and permit-V the pump), until the normal values. i

The diaphragm unit controls the pump in normal operation. This unit `is responsive to the low suction pressures of adapted to close as the suction pressure decreases. Thus, as the pressure slows to a point where it is just able to maintain, a lbs'.` suction pressure, and `the pump operatesjto pump exactly'thesame amount of liquid it receives from the line.

The operation of the above control systemwill be described with regard to a pipe line schematically illustrated by the diaphragms oi Figs. 2, 3 and 4. 1

Such pipe line may co sist, by way of an illustrative example, of a 4-inch4 diameter spiral welded pipe provided with so-called Victaulic couplings, and having pump-stations of the type described above spaced at distances of approximately miles from each other, as shown at A, B, C, D and E. The pipe line is likewise provided with gate `valves a, b, c and d, installed at regular intervalsand also at points such as road, river or railroad crossings, steep grades, and other points exposed to hazard. whereby the flow inthe pipe line may be stopped at any desired point.

Such line, with the `stations equipped with` proper high pressure pumps and prime-movers, may be adapted to handle gasoline at a basic flow rate of about 200 barrels per hour with all stations running, or at someotherdesired rate, such, for example, as'l'75 or 165 barrels per hour with any number of stationsshut down, provided no two adjacent stations are shut do'wn. The line pressure drop will be about 20 lbs/sq. in.

per mile at the 200 bbls./hr. iiow rate, and of l4 lbs/sq. in. at the 165 bbls./hr. flow rate.

i If the theoretical line of five stations and intervening and downstream sections shown in Fig. 2` is considered, all possible combinations of operating conditions can be readily analyzed and determined,and the results and conclusions will hold true for any number of VVfurther sections which may be added to the pipe line. of possible intermediate withdrawals is neglected, since it results `merely in reducinf1r pressures and simplifying operations.

With all the stations running, the first station A is adjusted to operate at about 400 lbs. discharge pressure, which isprovided by the line resistance of about 20 lbs. per mile for the 20- mile section between stations A "and B', the line delivering 2M .barrels per hour.` Each of the succeeding stations will operate in the same manner, the high pressure and suction relief Valves I and 2 being closed and the prime-mover and pump being maintained under control by the adjustable orifice control l!! and the low-suction throttle control 5 at a proper speed and a suction pressure of about 10 lbs.

With stations A and B operating continuously, and one of the stations, for example, station C, shut down, the operation of the line is shown in Fig. 3. i

Station A will operate, as in the rst case, at a discharge pressure of 400 lbs. Since, due to the failure of station C, the line is capable of delivering only about 165 bbls. per hour, the

pressure drop over the `20-mile section A--B at a rate of 14 lbs. per mile will be 280 lbs., and station B will operate at a suction pressure of the pump 2li, and isV falls,Y the engine i The effect scribed with'regard to the pressure, such while the downstream stations are taking only about bbls. per hour.' i I 1 Station C will be by-passed through open Valve I2, I3 and I4, valves l being closed. Station D will operate on its low suction throttle control 5, engine and the pump slowingdownto handle about 165 bbls. per hour.` sure of station D will be about 280 to 325.1105., as required to pump to station E. Station E will operate in a manner similar to that of station D. Substantially the same mode -of operation will prevail if any other station, such for example, as D, is temporarily cut out of the line. i If, with all stations operating it; it becomes necessary due to an emergency, to shut down the whole line by closing, for example, a valve c between stations C and D, as shown inFig. .4, the stationC will come up; to a discharge pressure of 625 lbs.,

down the prime-mover 60. The discharge pressure will, however, continue rising `until it` reaches 650 lbs., at which point the highdischarge relief valve I willv open, permitting the tion side of the pump through towards the value of the station discharge pressure. At 400 lbs. suction pressure the highsuction relief valve 2 the station. The suction pressure being thus broughthigher than done by the pump lating the liquid from tion side.

, The sequence oi' automatic operations deutively repeated at stations pressureV rise due to reaches ,these stations.

trol 3 of the station valve c at a desired pressure, such as 500 lbs.

Stations Dand E lose suction and are brought When the closed` gate tion pressure of the downstream stations D'and E, which thereupon resume operations.

At the same time, the pressure of the next upstream station C, which had been maintained at a high value such as 500 lbs., begins to drop until the suction pressure of said station is sufficiently low to open the high suction throttle control 4 and close the high suction relief valve 2 (which will happen respectively at 425 and 400 lbs.) whereupon the station will resume operations on normal control basis. This reduction of pressure will similarly affect each successive upstream station, each of said stations in turn resuming pumping until the operation of the whole system is again normal. l

If two adjacent stations, for example, B and C, are shut down simultaneously, and the previous upstream station, A, is not able to pump through these two stations to the next downstream sta- IB and I'I shown in liig.`

at about 10 lbs., the- The discharge presi Yat which point the high dis-l charge throttle control 4 will operate, slowing will open, completely equaliz` ing the discharge and the suction pressureofV 425 lbs., `the high suction.. throttle control 4 will operate, bringing the 1 prime-mover to idling` speed, whereby the work` i 20 will be limited to recircu' the discharge to the` sucstation C is consec-i B and A, when the', the closure of the valve c* A proper adjustment of; the stop 3l on the high discharge throttle con-1. A causes said station to` lmaintainfthe whole 'system up to the blocked tion, D, the same;sequenceofoperationsrwill take `place-las described for the case offazvalve-c shuttingdown theline.

lt will' thus be seen that;the present invention provides a eXible system. of pipe linel control, whereby-'La line can beoperated at `anyl desired ow rate .upto maximum .pressure Vcapacity, that is, for. the example given, hereinabove, within a rangeof from; about three barrels per-hour.v to about twohundredbarrels or more per hour, saidl maximum capacity depending'on the actual line resistance. f f

lIzt'clesired; withdrawals of theliquid maybe effectedat: any desired: points along the line, the present automatic controlalways permitting the line. toldeliver. to ther-end point such liquid as .re-

mains after withdrawals` or: after individual` orv multiple -station shutdowns,

Iiclaimas my inventionz' ltnfapipe line system, the combination of'av a suction inlet connecting said` pipeline, apump, pump with the pipe line,- a dlschargevoutlet 'having. vtwo parallelv branches connecting said pump with 'twospacedl points inl the pipeline downstream-ofthe inlet, normally closed pressureactuated-valve means in-the outlet branch near.- estfthelinleti adapted to open in'response to apredetermined high discharge pressure, andk normally closed pressure-actuated valve means in the'. pipe line betweenv the two outlet branchesV adapted toiopen in response to apredetermined high/suction pressure.

2f. Inapipe line'system, the combination of a pipefline, a conduit connected in parallel with said-pipe line at spaced' points-thereof, a Valve adaptedzto vclose the pipe linebetween said points, af pump,l aniinlet'passagebetween the suction side ofsaidr pumpv and said conduit, an outlet passage-having two parallelfbranchesy between the pointsiof said'conduit downstream of the inlet passage, normally closed valve means in the outlet," branch nearest. the inlet, adjustablev means responsive to a predeterminedv high discharge pressure adapted to open said valve, normally closed valvemeans .ina said i conduit between said.

twooutlet branches, and vadjustable means responsive toa predeterminedhighsuction pres` sure adapted to open said valve.

3;'In a pipe line system, the combination of a pipe line, a-l conduit connected in parallel with saidpipe lineat spacedl points thereof, a valve adaptedfto-close the pipe line between said points, aepump, a prime-mover,y for said'pump, anv inlet passage 'between the suction` side of the pump and' said,` conduit, an-` 'outlet' passage having two parallel branches betweenthe discharge side of said pumpand'two spaced points of said conduit downstream of the inlet passage, normally closed discharge side of saids-pump andl two spaced pressure-actuated'rst valve means in the outlet branch nearest the inlet adapted to open in response to a predetermined high discharge pressure, normally closed pressure-actuated second' second valve means, and pressure-actuated control means adapted to cause said regulator to reduce the speed of thev prime-mover in response to a predetermined low suction pressure.

4. In a pipe line system, the combination of a pipe line, a conduit connected in parallel with said pipe line at spaced points thereof, a valve adapted to close the pipe line between said points, a pump, a prime-mover for said'pump, an inlet passage between the suction side of the pump and said conduit, an outlet passage having two parallel branches between the discharge side of said pump and two spaced points of said conduit downstream of the inletfpassage, normally closed pressure-actuated rst valve means in the outlet branch nearest the inlet adapted to open in responseV to a predetermined high discharge pressure, normally closed pressure-actuated second valve means in said conduit between the two outlet branches adapted to open in response to a predetermined high suction pressure, a speed' regulator for the pump prime-mover, a control:

pump driven by said prime-mover, a closed liquid circuit between the suction andythe discharge sides of said control pump, adjustable orice means adaptedto restrict the now in said circuit, diaphragm-controlledorifice means responsive to high pipe line pump discharge pressure to restrict the flow in saidl circuit, diaphragmcontrolled orifice means responsive to high pipe line pump suction pressure adapted to restrict the flow 'in said circuit, diaphragm-controlled orifice means responsive to low pipe line pump suction' pressure adapted to restrict the flow cuit, the pressure in said circuit at a particular pumping rate varying. as a function of the ow therethrough, andv diaphragm' means responsive to the pressure in said circuit adapted to actuate the speed regulator of said primemover, whereby the speed of said prime-mover is varied.

in said cir- SYDNEY S. SMITH.

prime-mover in responseto a predetermined high suction pressure, said pressure being above that required to open said adapted 

